There are numerous varieties of ball point pens manufactured today. One category of ball point pens manufactured include pens with replaceable ink cartridges. With such pens, a refill ink cartridge can be substituted for the exhausted ink cartridge, restoring the usefulness of the pen once the ink supply is exhausted. With the wide variety of ball point pens manufactured today to appeal to the wide variety of individual tastes, the size and shape of these pens and refills varies considerably. The differences in the structure of these pens results in differences in the structure of housing in which the pen refill cartridge must be placed and in the configuration and dimensions of the ink cartridge itself.
The proper functioning of a pen depends upon whether the refill cartridge is adapted to fit within the housing in which the refill cartridge is used. If the cartridge does not fit properly, the cartridge will not extend and retract properly within the housing. Among the problems that can result are: the ink may not flow; if the cartridge is too short, the ball point tip on the cartridge may not reach the writing surface; if the cartridge is too long, the tip may be subjected to excessive forces, or the ball point tip may automatically retract into the housing. As a result, standard refill cartridges cannot fit all different makes and models of pens manufactured today. A device which can adapt refill cartridges to fit a wide variety of different pen housings is desirable. With the constant change in the structure of commercial pens, stores cannot possibly stock refill cartridges to fit every pen manufactured. Moreover, with so many different sized refill cartridges available, finding the proper sized cartridge that fits a particular pen leads to confusion of both the merchant and the customer.
Prior attempts have been made to develop adapters which can be used with a variety of refill cartridges. These adapters alter the length of the cartridge enabling it to fit into different sized ball point pen housings. One such device employs adapters of varying lengths sold as a kit. These adapters can be either screwed on or plugged into a standard sized cartridge to elongate the cartridge. In general, the length of the adapters sold in the kit correspond to the most popular pen sizes in use. One problem with this approach is that it is wasteful. One is required to purchase an entire kit to obtain the one adapter that is needed to adapt a cartridge to fit a particular pen. In addition, if a consumer purchases a pen whose size does not correspond to the adapters provided in the kit, the adapters will be inappropriate, and the consumer must buy a cartridge specifically designed for their pen.
Further, unless the ink cartridge is pressurized, the ink inside a cartridge will not properly dispense the ink. Some kit-type adapters require that a small hole be drilled in the side of the cartridge after the adapter is mated with the cartridge to provide ventilation. If the hole is not properly made in the cartridge, the cartridge may leak or not provide an adequate flow of ink.
A second prior art approach employs refill cartridges with segmented scribed lines. Once the necessary length of the refill cartridge required to fit within the pen housing is determined, the refill cartridge is bent along the scribed lines closest to the length of the exhausted cartridge and the excess portion of the refill cartridge is thereby removed. One disadvantage of this type of adaptable refill cartridge is that the cartridge itself must be bent to break off the segments. If the bending is not properly done, the ink may dispense from the cartridge or additionally, ventilation of the ink supply may be inhibited, preventing the proper flow of ink. A second disadvantage of this type of segmented refill cartridge is that the consumer is prevented from buying a refill cartridge of his choice. With this device, the cartridge itself is adapted to obtain the necessary size required for the pen housing. If the type of ink or ball point tip used with this cartridge is not to the customer's liking, this device is unacceptable. This adaptable refill cartridge further requires merchants to stock, in addition to the regular standard refill cartridges, a wide variety of ink types and ball point tip sizes for these adapter cartridges. Moreover, refill cartridges of this type are typically more expensive than standard refill cartridges.
None of the known prior art devices solves the need for adapting standard pen refill cartridges to fit a variety of pen housings. Thus, a need exists for an inexpensive, efficient, easy to use adapter which can be used with many different types of standard refill cartridges to increase their length to enable them to fit within a variety of pen housings.